INCREASED PLASMA AMYLOID-BETA PROTEIN-1-42 LEVELS IN DOWN-SYNDROME

Amyloid beta protein 1-40 (A beta 40) and A beta 42 levels were quanti tated in plasma from 43 persons with Down syndrome (DS; 26-68 years of age), 43 age-matched normal controls, and 19 non-DS mentally retarded (MR) persons (26-91 years of age) by using a sandwich enzyme linked i mmunosorbent assay. A beta 40 levels were higher in DS and MR than con trols, but were similar between DS and MR groups. A beta 42 levels wer e higher in DS than controls or MR persons. The ratios of A beta 42/A beta 40 were higher in DS than controls or MR persons. The findings ar e consistent with those seen in DS brains. (C) 1998 Elsevier Science I reland Ltd.